Multiplayer doesn't need to be in every game, but I can see how a game not having it could be considered a knock against it. If it is a game that lends itself to multiplayer doesn't capitalize on that then that is a missed opportunity and pointing that out is a valid criticism. I think it is over/missed used as a criticism as this often leads to games that are made as a single player experiences then have multiplayer experiences tacked on (Bioshock 2) because apparently no one is allowed to like a single player experience unless multiplayer is shoe horned in (thank you game critics).

Adding multiplayer to a game isn't a bad thing as it is something you didn't have before that you now have. You can choose to ignore it or engage in it at will and so if you don't like it fine, it doesn't affect the single player experience. What is bad about it is the opportunity cost, it might not be bad in and of itself but the developer spent money making it that might of gone to making the rest of the game better. Often times multiplayer isn't bad because it is bad but because we could of had a better version of the good parts of the game (the same thing can be said about multiplayer games that shoe horn in single player experiences).

I'm talking about this because I often seen similar complaints about linear gameplay and while I'm (kinda) fine with the ones about multiplayer the complaints about linear gameplay are flat out wrong. I often read reviews (because I'm a hypocrite) where they say they like the game but it is very linear and wished it was a bit more open and often open gameplay is talked about as something intrinsically better, it isn't. Multiplayer is modular, in that adding it doesn't affect single player, but linear vs open progression is a distinct choice each conferring different advantages. Open gameplay offers the player the freedom to create their own story and it is pretty great, and since it is typically held up as the better of the two I don't feel the need to defend it (right now) and so I'm going to talk about the advantages of linear gameplay a bit. Linear gameplay does offer a huge advantage over open gameplay, control.

When you keep a tight rein over what you let the player do you can create a constant difficulty level and narrative. When the player can do anything in any order how could you possibly tell a story? If you have ever played Skyrim, I'm sure you know the feeling of being told to do something gravely important only to blow it off and go punch a mammoth. It is great and all, but it makes telling a story with any kind of gravitas or urgency impossible.

I'm willing to meet everyone halfway on this one, how about instead of talking about a game being 'too linear' we say it is 'more linear then needed' or 'linear without using the inherent advantages of linearity'? There are certainly games that are very linear but don't' use it to craft an experience, and wouldn't be made less for opening up a bit but those are different from games that are super linear and use that to its full advantages.